Chair base



FIG. 1 is a front right perspective view of a chair base embodying our new design.

FIG. 2 is a right side elevational view of the chair base of FIG. 1.

FIG. 3 is a left side elevational view of the chair base of FIG. 1.

FIG. 4 is a front right elevational view of the chair base of FIG. 1.

FIG. 5 is a front left elevational view of the chair base of FIG. 1.

FIG. 6 is a top plan view of the chair base of FIG. 1; and,

FIG. 7 is a bottom plan view of the chair base of FIG. 1. 

I claim the ornamental design for a chair base, as shown and described. 